Loathe as I am to get involved in pointless discussions when people don't want to know the answers, I expect you would struggle to bounce anything off the sun as it is giving out massive amounts of light that would swamp your laser. It would work with the Moon though.

Calculating the distance to the Sun requires careful, accurate observations, but then it's just geometry. The ancient Greeks had a go, but lacked the former.

https://www.universetoday.com/117843/how-did-we-find-the-distance-to-the-sun/
https://www.space.com/17081-how-far-is-earth-from-the-sun.html

I expect thousands of astronomers have taken measurements that will confirm the numbers. The distance does vary as our orbit is not a perfect circle. That was known hundreds of years ago.

We can see the Sun because it is so freaking enormous, as are the stars.

You say you hate maths, but just because you don't understand something does not make it untrue. If you make outrageous claims then you need extraordinary evidence and there are knock-on effects, e.g. if the Sun is close and small then how does it stay hot and what keeps it up? You may do down the concept of theory of gravity, but in science a theory needs to be tested and that one has been for hundreds of years. There have just been minor adjustments for things like relativity which come into play in extreme conditions. Newton got a lot right.

But believe what you want. The engineers and scientists will rely on real evidence.